<!--  -->
<template>
            <!-- 商品分类导航 -->
        <div class="type-nav">
            <div class="container">
                <div @mouseleave="leaveIndex">
                    <h2 class="all">全部商品分类</h2>
                    <div class="sort">
                        <div class="all-sort-list2" @click="goSearch">
                            <div class="item" v-for="(c1,index) in categoryList" :key="c1.categoryId" :class="{cur:currentIndex==index}">
                                <h3 @mouseenter="changeIndex(index)">
                                    <a :data-categoryName="c1.categoryName" :data-categoryId="c1.categoryId">{{c1.categoryName}}</a>
                                </h3>
                                <div class="item-list clearfix" :style="{display:currentIndex==index?'block':'none'}">
                                    <div class="subitem" v-for="(c2,index) in c1.categoryChild" :key="c2.categoryId">
                                        <dl class="fore">
                                            <dt>
                                                <a  :data-categoryName="c2.categoryName" :data-categoryId="c2.categoryId">{{c2.categoryName}}</a>
                                            </dt>
                                            <dd>
                                                <em  v-for="(c3,index) in c2.categoryChild" :key="c3.categoryId">
                                                    <a  :data-categoryName="c3.categoryName" :data-categoryId="c3.categoryId">{{c3.categoryName}}</a>
                                                </em>
                                            </dd>
                                        </dl>
                                    </div>
                                </div>
                            </div>
                        </div>
                    </div>
                </div>
                
                <nav class="nav">
                    <a href="###">服装城</a>
                    <a href="###">美妆馆</a>
                    <a href="###">尚品汇超市</a>
                    <a href="###">全球购</a>
                    <a href="###">闪购</a>
                    <a href="###">团购</a>
                    <a href="###">有趣</a>
                    <a href="###">秒杀</a>
                </nav>
            </div>
        </div>
</template>

<script>
import {mapState} from 'vuex';
import  throttle from 'lodash/throttle';
export default {
    name: 'TypeNav',
    data() {
        return {
            //存储用户鼠标移到哪一个
            currentIndex: -1,
        }
    },
    //组件挂载完毕，向服务器发请求
    mounted(){
        //通知vuex发送请求 获取数据 存储于仓库中
        this.$store.dispatch('categoryList')
    },
    computed:{
        ...mapState({
            // 右侧需要的是一个函数 当使用这个计算属性时，右侧函数会执行一次
            // 注入一个参数state 其实为这个大仓库中的数据
            categoryList:(state)=>{
                return state.home.categoryList;
            }
        })
    },
    methods: {
        //鼠标进入修改响应式currentIndex属性
        changeIndex: throttle(function(index){
            //index 鼠标以上某一个分类元素的索引值
            this.currentIndex=index
        },50),
        //一级分类鼠标移除
        leaveIndex(){
            this.currentIndex=-1;
        },
        goSearch(event) {
            let element = event.target
            let {categoryname,category1id,category2id,category3id} = element.dataset;
            if (categoryname){
                let location = {name: 'search'};
                let query = {categoryName: categoryname};
                if (category1id) {
                    query.category1Id=category1id;
                } else if(category2id) {
                    query.category2Id=category2id;
                }else{
                    query.category3Id=category3id;
                }
                location.query=query
                console.log(location);
                this.$router.push(location)
            }
        }
    }
    }
</script>
<style lang='less' scoped>
    .type-nav {
        border-bottom: 2px solid #e1251b;

        .container {
            width: 1200px;
            margin: 0 auto;
            display: flex;
            position: relative;

            .all {
                width: 210px;
                height: 45px;
                background-color: #e1251b;
                line-height: 45px;
                text-align: center;
                color: #fff;
                font-size: 14px;
                font-weight: bold;
            }

            .nav {
                a {
                    height: 45px;
                    margin: 0 22px;
                    line-height: 45px;
                    font-size: 16px;
                    color: #333;
                }
            }

            .sort {
                position: absolute;
                left: 0;
                top: 45px;
                width: 210px;
                height: 461px;
                position: absolute;
                background: #fafafa;
                z-index: 999;

                .all-sort-list2 {
                    .item {
                        h3 {
                            line-height: 30px;
                            font-size: 14px;
                            font-weight: 400;
                            overflow: hidden;
                            padding: 0 20px;
                            margin: 0;

                            a {
                                color: #333;
                            }
                        }

                        .item-list {
                            display: none;
                            position: absolute;
                            width: 734px;
                            min-height: 460px;
                            background: #f7f7f7;
                            left: 210px;
                            border: 1px solid #ddd;
                            top: 0;
                            z-index: 9999 !important;

                            .subitem {
                                float: left;
                                width: 650px;
                                padding: 0 4px 0 8px;

                                dl {
                                    border-top: 1px solid #eee;
                                    padding: 6px 0;
                                    overflow: hidden;
                                    zoom: 1;

                                    &.fore {
                                        border-top: 0;
                                    }

                                    dt {
                                        float: left;
                                        width: 54px;
                                        line-height: 22px;
                                        text-align: right;
                                        padding: 3px 6px 0 0;
                                        font-weight: 700;
                                    }

                                    dd {
                                        float: left;
                                        width: 415px;
                                        padding: 3px 0 0;
                                        overflow: hidden;

                                        em {
                                            float: left;
                                            height: 14px;
                                            line-height: 14px;
                                            padding: 0 8px;
                                            margin-top: 5px;
                                            border-left: 1px solid #ccc;
                                        }
                                    }
                                }
                            }
                        }

                    }
                    .cur{
                        background: skyblue;
                    }
                }
            }
        }
    }
</style>